This invention relates to a method for preparing metal organic compounds. More particularly, this invention relates to a method of preparing hydrocarbon substituted dithiocarbamates of molybdenum.
Processes for preparing hydrocarbon substituted dithiocarbamates of molybdenum have been proposed heretofore. In one such process, stoichiometric quantities of ammonium hydroxide, a dihydrocarbyl substituted amine and carbon disulfide are combined in water to produce a dihydocarbyl substituted alkali metal salt of a dithiocarbamate. The dihydrocarbyl substituted sodium salt of dithiocarbamate is then reacted with an alkali metal molybdate in the presence of acid to produce monomers and dimers of a dihydrocarbyl substituted dithiocarbamate of molybdenum. In general, the alkali metal molybdate is used at a concentration within the range from about 1.5 to about 2 moles per mole of alkali metal salt of a dithiocarbamate. The dimer produced during the acidification may be oxidized back to the monomer with a suitable oxidizing agent such as a peroxide or hydroperoxide. When an oxidizing agent is used, it is, generally, used in an amount ranging from about 0.2 to about 0.5 moles per mole of total molybdenum present in the reaction mixture.
While the process thus described has been effective in the production of dihydrocarbyl substituted dithiocarbamates of molybdenum, the product generally contains significant quantities of impurities (by-products) such as tetralkylthiouran disulfide, polysulfides and tars, which by-products lead to a reduced purity and yield. Since certain of these impurities are not easily separated from the product, thereby detracting from its ultimate final use, and since the yield resulting from this process is, generally, less than normally desired in a chemical process, the need for an improved process for the production of dihydrocarbyl substituted dithiocarbamates of molybdenum is believed to be readily apparent.